The genus Microptila Ris (Trichoptera, Hydroptilidae) in Japan Author Ito, Tomiko text Zootaxa 2017 4232 1 104 112 journal article 36543 10.11646/zootaxa.4232.1.7 23068eb9-dd4a-4eb8-a613-10fe4bfba459 1175-5326 292743 7C3A4400-CCA5-4E9E-82BA-F8B931BC3F9B Microptila nakama sp. nov. ( Figs 3 , 4 C, 5) Diagnosis . The male of this species shows some similarities to Microptila pasak Wells 1993 , described from Bali , Indonesia , in having the subgenital plate bilobed distally, these lobes divergent, and a short apical or subapical process on each inferior appendage, but is distinguished from that species as follows: (1) Segment IX with rounded posterolateral angles ( Fig. 3 A, cf , IX with digitiform lobes laterally in M. pasak ); (2) the caudal excavation of the subgenital plate is narrow and deep ( Fig. 3 B, 3D, cf , the excavation wide and shallow in M. pasak ); and (3) the inferior appendages each have a short mesal process subapically ( Figs. 3 A,3C,3E, cf . the inferior appendages each have a peg-like process at the mesal-caudal corner in M. pasak ). FIGURE 2. Microptila genka sp. nov. male and female, type specimens. Male (2A–2F): 2A, genitalia, left lateral; 2B, same, dorsal; 2C, same, ventral; 2D, subgenital plate, dorsal; 2E, right inferior appendage, ventromesal; 2F, phallus, left lateral. Female (2G): 2G, abdominal segments VII–X, ventral. Abbreviations: VII–X = abdominal segments VII–X; inf app = inferior appendage (paired); ph = phallus; sg plate = subgenital plate; ti = titillator; t X = tergite X. FIGURE 3. Microptila nakama sp. nov. male, type specimens. 3A, genitalia, left lateral; 3B, same, dorsal; 3C, same, ventral; 3D, subgenital plate, dorsal; 3E, left inferior appendage, ventromesal; 3F, phallus, left lateral. Abbreviations: IX–X = abdominal segments IX–X; inf app = inferior appendage (paired); ph = phallus; sg plate = subgenital plate; ti = titillator; t X = tergite X. Male . Length of each forewing and hind wing 1.4–1.6 mm and 1.2 mm , respectively (n = 2). Antennae 18–19- segmented and 0.6 mm long (n = 2). Genitalia ( Figs. 3 A–3F). Segment IX (IX) annular, in dorsal view ( Fig. 3 B) excavation of anterior margin deep and semi-circular, excavation of posterior margin deep and quadrate, transverse tegmental bridge broad, dorsal midline about 1/5 as long as segment IX; in ventral view ( Fig. 3 C) excavation of anterior margin shallow and semicircular, excavation of posterior margin shallow and quadrate. Tergite X (t X) quadrate, in dorsal view ( Fig. 3 B) with subquadrate excavation caudally, semimembranous and transparent with lateral margins lightly sclerotized. Subgenital plate (sg plate) large, strongly sclerotized, margins of basal half rounded laterally, distally bilobed, lobes slightly divergent ( Figs. 3 B, 3D); in lateral view ( Fig. 3 A) stout, rod-shaped, slightly curved ventrad. Inferior appendages (inf app) large, setose; in lateral view ( Fig. 3 A) main article stout at basal 4/5 and strongly tapered in apical 1/5; in ventral view ( Fig. 3 C) apices incurved, in ventral and ventromesal views ( Fig. 3 C, 3E) blunt mesal process subapically. Phallus long, slender, titillator (ti) arising at apical 1/3, encircling phallus 1.5 times ( Fig. 3 F). FIGURE 4. Type localities of the 3 Japanese species of Microptila . 4A, M. orienthula (Japan, Hokkaido, Shiriuchi-cho, hygropetric zone beside Idesu-gawa,1 July 2008); 4B, M. genka (Japan, Ryukyu Islands, Okinawa-jima, Nago-shi, Genka , hygropetric zone near Hogen-hashi, 26˚36’16” N, 128˚04’29” E, 65 m a.s.l., 18 March 2012); 4C, M. nakama (Japan, Ryukyu Islands, Iriomote-jima, Nakama-gawa river system, Nishi-funatsuki-gawa, Nishi-funatsuki-bashi, 24˚18’10” N, 123˚51’34” E, 10 m a.s.l., 1 March 2016) (Images by Shizuko Morimoto). FIGURE 5. Distribution of the 3 Japanese species of Microptila . The boundary between East Palearctic and Oriental Regions is modified from Morse 2016. Female . Unknown. Holotype : male, Japan , Ryukyu Islands , Iriomote-jima , Nakama-gawa river system, Nishi-funatsuki-gawa, Nishi-funatsuki-bashi, 24˚18’10” N, 123˚51’34” E, 10 m a.s.l. , 30.x.2012 , T. Ito (CBM-ZI 151363). Paratype : 1 male , same data as holotype (CBM-ZI 151364). Etymology . The specific name ( nakama , a noun) refers to the river where this species was collected. Habitat ( Fig. 4 C). Adults of this species were collected from a fast-flowing stream with large boulders. Distribution ( Fig. 5 ). Japan (Ryukyu Islands: Iriomote-jima). Known only from the type locality. Japanese name . Nakama-mikuro-himetobikera.